Standardized Work and Kaizen
Standardized work is not the end point. It is the baseline for kaizen — the reference you improve against, and the thing you revise once the work gets better.
The basis of the Toyota Production System is standardization and the elimination of waste. Standardized work supplies the first; this section is about the second — how a stable standard lets you see waste, judge efficiency honestly, and improve the work in a disciplined way, then lock the gain back into the standard.
1No standard, no improvement
Improvement requires comparison. Without a defined standard, the work is done a little differently every time — conditions vary, and you can neither isolate the cause of a problem nor prove that a change actually made things better. Standardized work gives the current baseline. You improve against it, confirm the result, and then revise the standard so the gain is held and the next cycle starts from a higher level.
Do not call something kaizen if the standard is not changed afterward. Otherwise the organization learns improvement as an event, not as a managed change in the way the work is done.
2Work and waste
In TPS, not all motion is value-adding work. It helps to see the motion in any process as three parts: value-added work that advances the product in a way the customer pays for (machining, welding, assembling); incidental work that adds no value but is required by the process as it stands today (some walking, conveyance, or handling); and pure waste that adds nothing and should be removed first.
At most worksites the value-added share is small. Incidental work is the target for changing conditions; pure waste is the target for removal.
What to notice: raising efficiency is mostly about shrinking the right-hand bands — not about making the value-added work faster.
3The seven kinds of waste
Waste is any action that raises cost without adding value. TPS classifies it into seven kinds:
Making more than needed, or earlier than needed. The most serious waste — it creates and hides the others.
Fixing defects. The material, time, and energy spent on repair add no value — and repaired parts are often impaired.
Unnecessary work on the part — over-finishing non-critical surfaces, redundant checks, work beyond spec.
Transporting parts further or more often than the flow requires. Transport itself adds no value.
Excess stock between processes. It ties up money and hides the real causes of problems.
Non-value motion of people or machines — searching for parts, walking caused by poor layout.
Idle time — an operator watching a running machine, or a line halted while someone hunts for material.
Each is something to see and remove. Standardized work makes them visible by giving a stable pattern to compare against.
4Overproduction — the worst waste
Overproduction takes two forms: making more parts than required, and making them earlier than required — the right part at the wrong time. It is treated as the most serious waste because it creates and hides the others. Extra parts consume extra labor, machine time, and energy; they generate pallets, storage space, handling, and stock control; and the resulting buffer of inventory hides breakdowns and quality problems, so the need to fix them is no longer obvious.
Make only what is needed, when it is needed, in the quantity needed. Producing things that don't sell is waste.
5Unevenness and overburden
Waste has two close relatives. Together they are often called by their Japanese names — muda (waste), mura (unevenness), and muri (overburden):
Action that raises cost without adding value — the seven kinds above.
Fluctuation in schedules or workload. To avoid stopping the customer, plants carry enough for peak demand — leaving far too much the rest of the time.
Pushing people or machines past their limit. It causes fatigue and unsafe acts in people, breakdowns and defects in equipment.
They feed each other: unevenness in the schedule forces overburden at the peaks, which then produces defects, breakdowns, waiting, and extra inventory. Standardized work helps by making the expected, level pattern visible — and overburden is answered not by indulging fatigue but by training people, rotating through strenuous jobs, and making hard work easier through kaizen.
6True versus apparent efficiency
When demand needs to rise, the conventional answer is to add people, add equipment, or work longer — all of which assume output is fixed and raise cost. The TPS answer is to eliminate waste first: by cutting walking and waiting, or changing the sequence or layout, the same operator on the same machine might produce 120 parts an hour instead of 100. But whether that is real depends on one question — what is customer demand?
The numbers look better, but 20 units are overproduction. It is “efficiency” only on paper, and it generates the worst waste.
Meeting demand with fewer hours, less material, and fewer defects. This is real cost reduction.
Efficiency is judged against customer demand, not raw output. Producing more than is needed only looks efficient.
What to notice: judge improvement by its effect on the whole system. Halving the parts in one cell is individual efficiency; it matters only if it improves total flow from receiving to shipment.
Efficiency is not simply “more output.” True efficiency must be judged against customer demand and the effect on the total system — not the local count at one machine.
7The steps of kaizen
Kaizen is the disciplined, fact-based elimination of waste, with the responsible involvement of everyone — not the work of a few experts, and not something dictated from the top. It follows a simple scientific sequence:
- Clarify the goal — what to improve, and by how much; some problems are obvious (safety, quality, workability), but leaders should also seek them out.
- Analyze the present situation — get an accurate, quantitative grasp of the facts and root causes before going further.
- Generate ideas from the facts — many ideas, broad perspective; don't dismiss them too early.
- Make an improvement plan — weigh feasibility, cost, and how well it meets the goal; choose the best of several proposals.
- Implement with the people involved — secure cooperation across shifts and related areas, explain it, and train the new method.
- Evaluate the result — compare target with actual; if problems remain, counter them at once.
And then the step that secures everything: update the standardized work. If the standard is not revised, the improvement is not held — and the work quietly drifts back.
8Quality and safety
A stable standard also strengthens quality and safety. For quality, it lets you repeat the operation under identical conditions to find the true cause of a defect, make one piece at a time so defects show up immediately, and inspect at each process rather than after the fact — because quality has to be built in during production, not inspected in afterward. For safety, accidents most often happen where work is not standardized, or during out-of-the-ordinary troubleshooting; a clear standard, followed, greatly improves the odds of a safe workplace.
Section summary
Standardized work is the baseline for kaizen: without it you cannot isolate causes or prove a gain. It makes waste visible — the seven kinds, with overproduction the worst because it creates and hides the rest — and it exposes unevenness and overburden.
Efficiency is judged against customer demand and the whole system, not local output. Kaizen removes the waste through a disciplined sequence — and the final step is always to revise the standard, so the improvement is secured and the next cycle starts higher.